package com.dmm.vod.mapper;

import com.dmm.vod.entity.Subject;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import java.util.List;
import java.util.Map;

/**
 * <p>
 * 课程科目 Mapper 接口
 * </p>
 *
 * @author dmm
 * @since 2022-08-26
 */
@Mapper
public interface SubjectMapper extends BaseMapper<Subject> {

    @Select("select parent_id,count(parent_id) from `subject` GROUP BY parent_id")
    public List<Long> Groupsummation();

}
